Schedule ranking in Feb is like recruiting stars, it may shed some indication as to the future but you never know until they play.
Lets take UGAg from last year as an example. After 2 mickey mouse games(GSU and Central Michigan), they went to play SCeast who was speculated to be better than average but they didnt pan out. Then they went out to Zona St. who was returning a QB and team that was supposed to be on the up and up. ASU sucked last year. Bama killed them at home(during a blackout), no one picked Bama to be that good. Tennesse was supposed to be pretty good, they now have a new coach. Vandy was better than most people expected and hung in there. LSU was predicted to be a good team and they were in the Swamp. LSU couldnt find a QB yet and got killed. Florida and UK were as advertised. On to mighty Auburn (who may have been top 15 preseaon). Auburn now has a new coach. Finally the meek,hapless, helpless, struggling under a new coach/system, gonna win 3 games this year, havent beat UGAg in 7 years Jackets went into Samford Stadium and were a touchdown away from hanging half-a-hundred on them.
[INHALE....]
That tough schedule turned into only playing 4 ranked teams, only one of which they won (bowl game). Point being that analyzing SOS right now is a nice way to pass the time during the off season but it probably will be way off when all is said and done.